1. Field of Invention
The present invention pertains generally to power supplies and more particularly to pulsed DC power supplies that are used for generating plasmas that are used in thin film processing techniques for etching, deposition, etc.
2. Definitions
Alternating polarities means a current flow at any particular point in a circuit or plasma that changes direction, or a voltage at any particular point in a circuit that changes magnitudes around any desired neutral voltage.
Current connections means locations or points in a circuit that are coupled to electrodes of a plasma chamber.
Current controlled power source means a power source that is capable of maintaining a substantially constant current for a wide range of load impedances and has a low amount of capacitively stored energy.
Current reversing switches means any desired arrangement of switches that are capable of causing current to flow in different directions at a preselected location in a circuit.
Direct current means current that has a substantially constant magnitude.
Direction means the course of the flow of current on a conductor in a circuit.
Generating means initiating and/or maintaining.
Inductor means an electrical component that is designed to store energy in a magnetic field.
Plasma means a state of matter in which electrons and ions in a gas discharge are separated but together form a neutral assembly.
Plasma chamber means a device in which plasmas can be generated.
Power source means a device that is capable of supplying electrical energy.
Predetermined positions means either an opened or closed position of a switch.
Pulsed direct current means a current that flows at a particular point in a circuit that has a first substantially constant magnitude during a first period of time, and then has at least one additional substantially constant magnitude that is different from the first substantially constant magnitude during at least one additional subsequent period of time, and may repeat.
Substantially constant supply means a substantially constant magnitude.